Cylindrical drip irrigation emitter

ABSTRACT

A system including: (a) a pipe having an aperture providing fluid communication between inner and outer pipe surfaces; (b) a cylindrical drip emitter disposed within the pipe, including: an emitter body having an outer facing having a generally convex contour adapted in generally complementary fashion to a concave contour of the inner pipe surface, the outer facing secured to the inner surface; a liquid inlet section adapted to receive a liquid from within the pipe, and to deliver the liquid, via the aperture, to the outer facing; a pressure-reducing section disposed in fluid communication with the liquid inlet section; functionally active sections including the pressure-reducing section, the liquid inlet section, the functionally active sections disposed within, and longitudinally defining, a position of a longitudinal segment of the body; and at least one functionally passive section, disposed on the outer facing, within the longitudinal segment; and (c) a liquid flow path fluidly connecting between the liquid inlet section and the passive section, via the pressure-reducing section, and between the passive section and an ambient environment, via the first aperture, wherein the first aperture is situated within longitudinal bounds of the longitudinal segment, and radially aligned with the functionally passive section disposed within the longitudinal segment.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to drip irrigation emitters, and, moreparticularly, to compact cylindrical-type drip irrigation emitters.

Drip irrigation is a particularly efficient method of irrigating,particularly in arid environments. Water is slowly applied directly tothe soil, enabling the water to be quickly absorbed, whereby losses dueto evaporation or to run off are reduced. Drip irrigation systems may beutilized to irrigate a particular area around a plant. This furtherreduces water consumption and also reduces weed growth.

Market forces are continually demanding improved performance andimproved cost efficiencies for drip irrigation systems. While a plethoraof drip emitter types and species have been developed to meet variousneeds of the consumer, the present inventor has recognized a need forfurther improving the cost efficiency of cylindrical drip irrigationemitters.

SUMMARY OF THE INVENTION

According to the teachings of the present invention there is provided aliquid delivery system including: (a) a pipe having an inner surface andan outer surface, and at least a first aperture providing fluidcommunication between the surfaces; (b) a drip emitter disposed withinthe pipe, the emitter including: (i) an emitter body having an innerfacing and an outer facing, the outer facing having a generally convexcontour adapted in generally complementary fashion to a concave contourof the inner surface, the outer facing secured to the inner surface, thebody having a length L; (ii) a liquid inlet section adapted to receive aliquid from within the pipe, and to deliver the liquid to the outerfacing; (iii) at least one pressure-reducing section disposed in fluidcommunication with the liquid inlet section; (iii) functionally activesections including at least the pressure-reducing section and the liquidinlet section, the functionally active sections having a total lengthLa, the functionally active sections disposed within, and longitudinallydefining, a position of at least one longitudinal segment of the emitterbody; and (iv) at least one functionally passive section, disposed onthe outer facing, at least partially within the longitudinal segment;and (c) a liquid flow path fluidly connecting between the liquid inletsection and the passive section, via the pressure-reducing section, andbetween the passive section and an ambient environment, via the firstaperture, wherein the first aperture is situated within longitudinalbounds of the longitudinal segment, and radially aligned with a portionof the functionally passive section disposed within the longitudinalsegment; the outer facing spanning, in at least one location, an arccorresponding to an angle of at least 140° of the inner surface of thepipe.

According to further features in the described preferred embodiments,the functionally active sections include a pressure-controlling section.

According to further features in the described preferred embodiments,the functionally active sections consist of the pressure-reducingsection, the liquid inlet section, and a pressure-controlling section.

According to further features in the described preferred embodiments,the functionally active sections consist of the pressure-reducingsection and the liquid inlet section.

According to still further features in the described preferredembodiments, a length ratio of La to L of the emitter body is at least0.60 or at least 0.65.

According to still further features in the described preferredembodiments, this length ratio is at least 0.70, at least 0.75, at least0.78, at least 0.80, at least 0.82, or at least 0.85.

According to still further features in the described preferredembodiments, the inner facing has a diameter D, wherein an aspect ratioof the diameter D to length L is at least 0.25, at least 0.30, or atleast 0.34.

According to still further features in the described preferredembodiments, the outer facing spans, in at least one location, an arccorresponding to an angle of at least 180°, at least 225°, or at least270° of the inner surface.

According to still further features in the described preferredembodiments, the outer facing spans, in at least one location, an arccorresponding to an angle of 360° of the inner surface.

According to still further features in the described preferredembodiments, the emitter body is generally cylindrical.

According to still further features in the described preferredembodiments, the emitter body is generally cylindrical over all oflength La.

According to still further features in the described preferredembodiments, the emitter body is generally cylindrical over all oflength L.

According to still further features in the described preferredembodiments, the pressure-reducing section includes at least onelabyrinth channel.

According to still further features in the described preferredembodiments, the distance between a first end of the emitter body and aproximal end of the functionally active sections disposed proximally tothe first end, is less than 9 mm, less than 7 mm, less than 5 mm, orless than 4 mm.

According to still further features in the described preferredembodiments, the functionally active sections are substantiallylongitudinally continuous with respect to the body.

According to still further features in the described preferredembodiments, the pipe has at least one additional aperture disposedtherethrough, the additional aperture situated within length L, butlongitudinally outside of the longitudinal segment of the drip emitter.

According to still further features in the described preferredembodiments, the liquid inlet section includes a filtration section.

According to still further features in the described preferredembodiments, the outer surface of the pipe has at least one protrusionindicating a radial alignment of the emitter within the pipe.

According to still further features in the described preferredembodiments, the emitter has at least one alignment protrusion in theouter facing, the alignment protrusion at least partially protrudinginto the pipe.

According to still further features in the described preferredembodiments, the outer surface of the pipe has at least one mark,groove, or other external feature indicating a radial alignment of theemitter within the pipe.

According to still further features in the described preferredembodiments, an opening passes through the emitter body, whereby theinner facing and the outer facing are in fluid communication, the liquidinlet section adapted to receive the liquid from within the pipe, viathe inner facing, and to deliver the liquid, via the opening, to theouter facing.

According to still further features in the described preferredembodiments, the functionally passive section is disposed completelywithin the longitudinal segment.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings. With specific reference now tothe drawings in detail, it is stressed that the particulars shown are byway of example and for purposes of illustrative discussion of thepreferred embodiments of the present invention only, and are presentedin the cause of providing what is believed to be the most useful andreadily understood description of the principles and conceptual aspectsof the invention. In this regard, no attempt is made to show structuraldetails of the invention in more detail than is necessary for afundamental understanding of the invention, the description taken withthe drawings making apparent to those skilled in the art how the severalforms of the invention may be embodied in practice. Throughout thedrawings, like-referenced characters are used to designate likeelements.

In the drawings:

FIG. 1 is a side view of a drip irrigation emitter of the prior art;

FIG. 2 is a perspective view of the drip irrigation emitter of FIG. 1,disposed within a partially transparent irrigation pipe;

FIG. 3 provides a perspective view of a drip irrigation emitteraccording to an exemplary embodiment of the present invention;

FIG. 4 is an axially cut-open view of the drip irrigation emitter ofFIG. 3, disposed within a partially transparent irrigation pipe;

FIG. 5 provides a second perspective view of the drip irrigation emitterof FIG. 3;

FIG. 6 is a side view of the inventive drip irrigation emitter of FIG.3;

FIG. 7 is a perspective view of the inventive drip irrigation emitter ofFIG. 3, disposed within a partially transparent irrigation pipe;

FIG. 8 is a perspective view of another exemplary embodiment of theinventive drip irrigation emitter, disposed within a partiallytransparent irrigation pipe;

FIG. 9 provides a perspective view of a pressure-controlling dripirrigation emitter, according to another exemplary embodiment of thepresent invention;

FIG. 10 is a perspective view of another exemplary embodiment of theinventive drip irrigation emitter, the outer surface of the emitter bodyhaving an arc or contour of about 160°;

FIG. 11A is a perspective view of another exemplary embodiment of theinventive drip emitter, disposed within a within a non-cylindricalirrigation pipe;

FIG. 11B is a wire-rim drawing of the drip irrigation emitter of FIG.11A, in which the outer surface of the emitter body has a contour ofabout 250°;

FIG. 12A is a generally axial perspective view of another exemplaryembodiment of the inventive drip emitter, having alignment protrusionsdisposed in an outer facing of the emitter body; and

FIG. 12B is another perspective view of the drip emitter of FIG. 12A,disposed within a partially transparent pipe.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The principles and operation of the cylindrical drip irrigation emitteraccording to the present invention may be better understood withreference to the drawings and the accompanying description.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting.

With reference now to the drawings, FIG. 1 is a side view of a dripirrigation emitter 100 of the prior art. Drip irrigation emitter 100 isa cylindrical emitter, adapted to be bonded to an irrigation pipe 210,shown in FIG. 2. Emitter 100 includes a liquid inlet section 120, alabyrinth channel 130, and a liquid transfer section 140.

Liquid inlet section 120 fluidly communicates with labyrinth channel130, which in turn fluidly communicates with liquid transfer section140. Thus, water passes through liquid inlet section 120, into labyrinthchannel 130, and winds through labyrinth channel 130, ultimatelydischarging into liquid transfer section 140. The water exits liquidtransfer section 140 via an opening 142 disposed at each end thereof,and subsequently enters generally annular discharge regions 145, each ofwhich is distally located with respect to labyrinth channel 130, i.e.,towards each emitter end fixture 160.

FIG. 2 is a perspective view of drip irrigation emitter 100 of FIG. 1,disposed within irrigation pipe 210. According to methods of the priorart, during the extrusion-based process for producing irrigation pipessuch as irrigation pipe 210, drip emitters such as drip emitter 100 maytypically be affixed to the interior surface of the pipe, atsubstantially fixed intervals (time and distance). Apertures such asapertures 147 are formed through the wall of the irrigation pipe, basedon the estimated longitudinal position of each drip emitter within thepipe. More specifically, apertures 147 are formed through the wall ofthe irrigation pipe, based on the estimated longitudinal position ofannular discharge regions 145 of each drip emitter 100 within irrigationpipe 210. The longitudinal length Lp of each annular discharge region145 is typically 4-7 mm, to ensure that each aperture 147 is generallyaligned with a respective annular discharge region 145.

Water flowrate and optional pressure control are effected upstream ofannular discharge regions 145, such that the main function of dischargeregions 145 is to enable passage of the water into a discharge aperturein the wall of the pipe or conduit (as shown in FIG. 2). Thus, annulardischarge regions 145 may be considered substantially, functionallypassive length sections, in that they are disposed towards the end ofthe water flowpath, downstream of the pressure reduction section, andany pressure control section. The pressure reduction section (e.g., alabyrinth), and pressure control section of the drip emitter may beconsidered functionally active sections.

The market for drip irrigation systems is continually demanding improvedperformance and improved cost efficiencies for these systems. I haverecognized several deficiencies in discharge region 145, includingappreciable waste of raw materials, additional energy expenditure peremitter produced, relatively high shipping and storage volumes, andlower throughput of emitters through the feeding system.

Referring again to FIG. 1, the total length L of emitter 100substantially consists of the sum of the total length of a functionallyactive section 175 (described in greater detail hereinbelow), the lengthof each emitter end fixture 160, and the length of each annulardischarge region 145:

L=La+2·Le+2·Lp.

Significantly, the length ratio of the annular discharge regions to thetotal length of the prior art emitters may be at least 0.25, and moretypically, at least 0.30. In some of the more advanced, compact emittersof the prior art, the length ratio of the annular discharge regions tothe total length of the emitter body may be at least 0.35.

I have discovered that a method in which Lp may be substantiallyeliminated, enabling the use of a drip emitter that is at least 25-35%more compact with respect to emitters of the prior art. As will beelaborated in detail hereinbelow, the cylindrical-type drip emittersaccording to the present invention are designed to effect an at leastpartial discharge of the effluent water via a region that islongitudinally aligned with a functionally active section of theemitters, thereby obviating the need for the annular discharge regionsof the prior art.

With reference now to FIG. 3 and FIG. 4, FIG. 3 is a perspective view ofa drip irrigation emitter 300 according to an exemplary embodiment ofthe present invention. FIG. 4 is an axially cut-open view of dripirrigation emitter 300 of FIG. 3, disposed within irrigation pipe 210.Drip irrigation emitter 300 is an in-line, cylindrical emitter, adaptedto be disposed within, and secured within or attached (e.g., bonded) to,an irrigation pipe 210, shown in FIG. 4. Emitter 300 may include afiltration or liquid inlet section 320, at least one pressure-reducingsection such as a labyrinth channel 330 a, and at least one functionallypassive section or liquid transfer section such as section 340 a, asmall portion of which can be seen in FIG. 3.

Emitter 300 may advantageously have an emitter end fixture 360 on eachlongitudinal end of the emitter. Emitter end fixture 360 may beidentical or substantially identical to emitter end fixtures known inthe art, such as emitter end fixture 160 provided in FIG. 1.

FIG. 4 shows an inner facing 315 of emitter 300. Inner facing 315 mayadvantageously include a plurality of inlet openings or apertures suchas openings 326, which provide fluid communication between a volumecontained by inner facing 315 and an outer facing 350 of emitter 300. Aswill be appreciated by one of ordinary skill in the art, openings 326are adapted to inhibit coarse particles in the water from entering, andclogging, emitter 300.

The vast majority of the water within irrigation pipe 210 flows inlongitudinal fashion through emitter 300, and flows out into downstreamsection 212 of irrigation pipe 210. A minute fraction of the water flowsthrough openings 326, towards outer facing 350 of emitter 300. Havingpassed through filtration section 320, the water is now free to flowinto labyrinth channel 330 a. The flow of water exits labyrinth channel330 a via labyrinth intermediate channel 332, which may typically extendto an opposite side or face of emitter 300, shown in FIG. 5.

Over the course of the tortuous path of labyrinth channel 330 a, adesigned, pre-determined, or otherwise pressure drop may be achieved, aswill be readily understood by those of ordinary skill in the art.

FIG. 5 provides another perspective view of drip irrigation emitter 300,in which labyrinth channel 330 b and a functionally passive section orliquid transfer section 340 b are prominently displayed. Labyrinthchannel 330 b fluidly communicates with intermediate channel 332 (shownin FIG. 3), whereby the flow of water is discharged from intermediatechannel 332 into a first or proximal end of labyrinth channel 330 b.

The far or distal end of labyrinth channel 330 b fluidly communicateswith liquid transfer section 340 b. It may be advantageous, as shown inFIG. 5, for the distal end of labyrinth channel 330 b to fluidlycommunicate directly with a distribution passageway 335, which in turnfeeds into liquid transfer section 340 b, and preferably, into liquidtransfer section 340 a as well.

Liquid transfer sections 340 a (shown in FIG. 3) and 340 b have aparticular radial orientation with respect to the body of emitter 300.In exemplary emitter 300, each of liquid transfer sections 340 a and 340b are disposed on an arc or contour representing about 25% of the totalouter perimeter or circumference of emitter 300. It will be appreciatedby those of ordinary skill in the art that the number of liquid transfersections, as well as the individual and total fractions of the emitterperimeter or circumference, may vary due to various design constraintsor choices. It is critical, however, that the total fraction of theemitter perimeter or circumference be less than 1, and typically lessthan 0.8, less than 0.7, or less than 0.6, to enable the disposition ofat least one functionally active section (e.g., a pressure reducingsection or a pressure controlling section) substantially alongside theliquid transfer section or sections, within the same longitudinalsection or segment of the emitter body. This arrangement will beelaborated further with respect to FIGS. 6 and 7.

FIG. 6 is a side view of drip irrigation emitter 300. The length L ofemitter 300 includes the length of a first emitter end fixture 360 a(length=Le), at least one functionally active section such as section675 having a total length La along the body of emitter 300, and thelength of a second emitter end fixture 360 b. Emitter end fixtures 360a, 360 b are typically identical, such that the total length of thesefixtures is 2·Le.

Typically, length L of emitter 300 consists of, or substantiallyconsists of, the sum of the total length of functionally active section675 and the lengths of emitter end fixtures 360 a, 360 b:

L=La+2·Le.

In this exemplary embodiment, the length La of functionally activesection 675 is determined by the sum of the length of liquid inletsection 320 and the length of the labyrinth channel (e.g., labyrinthchannel 330 a). More generally, functionally active section 675 mayinclude a pressure controlling section (an exemplary embodiment of whichis provided in FIG. 9 and the associated description). Also, thesections of labyrinth channel provided herein are meant as exemplaryembodiments of pressure reducing sections. It will be appreciated thatvarious types of pressure reducing means and sections will be apparentto those of ordinary skill in the art.

Referring now to FIG. 7, FIG. 7 is a perspective view of inventive dripirrigation emitter 300, disposed within irrigation pipe 210. In emitter300, water or liquid discharged from functionally active section 675 maycollect within functionally passive section or liquid transfer section340 b, or between section 340 b and an inner surface 712 of pipe 210. Adischarge aperture 747 is disposed in the wall of pipe 210, such thatsection 340 b may fluidly communicate with, or directly fluidlycommunicate with, an environment outside of pipe 210, via aperture 747.

Discharge aperture 747 is both longitudinally aligned within alongitudinal segment defined by functionally active section 675, andradially aligned with functionally passive section 340 b. Inadvertentmisalignment of discharge aperture 747, whereby aperture 747 is radiallyaligned with a functionally active section, may severely compromise ordestroy the function of the emitter.

Referring back to FIG. 6, obviation of the annular discharge regions ofthe prior art cylindrical emitters enables an increased ratio of thetotal length La of the functionally active sections to length L of theemitter body. This length ratio may be at least 0.60, or at least 0.65,and more typically, at least 0.70, at least 0.75, at least 0.78, atleast 0.80, at least 0.82, or at least 0.85.

FIG. 8 is a perspective view of another exemplary embodiment of a dripirrigation emitter 800 according to the present invention, disposedwithin a pipe 810. As with drip irrigation emitter 300 provided in FIG.7, water or liquid discharged from the functionally active section ofthe emitter may collect within functionally passive section or liquidtransfer section 340 b, or between section 340 b and an inner surface812 of pipe 810. A discharge aperture 747 is disposed in the wall ofpipe 210, such that section 340 b may fluidly communicate with, ordirectly fluidly communicate with, an environment outside of pipe 810,via aperture 747. Discharge aperture 747 is both longitudinally alignedwithin a longitudinal segment defined by functionally active section675, and radially aligned with functionally passive section 340 b.

Drip irrigation emitter 800 has a generally annular discharge region845, which may be substantially similar to annular discharge region 145described with respect to FIG. 1. Annular discharge region 845 isdisposed between functionally active section 675 and emitter end fixture160. An additional aperture 847 is formed through the wall of pipe 810,based on the estimated longitudinal position of annular discharge region845 of each drip emitter 800 within irrigation pipe 810.

FIG. 9 provides a perspective view of a pressure-controlling dripirrigation emitter 900, according to another exemplary embodiment of thepresent invention. As described hereinabove, the pressure-controllingsection forms a portion of the functionally active section of theemitter. The pressure-controlling section is not described in detail,being well known to those of ordinary skill in the art of irrigationdrip emitters.

FIG. 10 is a perspective view of another embodiment of a drip irrigationemitter 1000, according to the present invention. In this exemplaryembodiment, an outer surface 1105 of emitter 1000 has an arc or contour(a) of about 160°. The outer surface of the drip emitters of the presentinvention typically span at least 140°, at least 160°, or at least 180°.

FIG. 11A is a perspective view of a drip emitter 1100 according toanother exemplary embodiment of the present invention, disposed within anon-cylindrical irrigation pipe 1110 having a non-cylindrical contour.

FIG. 11B is a wire-rim drawing of drip irrigation emitter 1100. In thisexemplary embodiment, an outer surface 1105 of the emitter body has acontour (a) of about 250°.

FIG. 12A is a generally axial view of a drip emitter 1200 according toanother exemplary embodiment of the present invention, having alignmentprotrusions 1292, 1294 and 1296 disposed in an outer facing 1205 ofemitter 1200. Alignment protrusion 1296 may be disposed on a radiallyopposite side of emitter 1200, with respect to alignment protrusions1292, 1294.

FIG. 12B is a perspective view of drip emitter 1200, disposed within apipe 1210. Typically, drip emitters such as drip emitter 1200 areinserted into an irrigation pipe such as pipe 1210, after the pipe hasbeen extruded. Alignment protrusions 1292, 1294 may be adapted whereby,during the insertion of drip emitter 1200 into pipe 1210, externalprotrusions are formed in an outer surface 1212 of pipe 1210.Consequently, the radial alignment of emitter 1200 within pipe 1210 maybe observed or determined based on the radial positioning of theseexternal protrusions.

Knowing the radial alignment of emitter 1200 within pipe 1210 may beimportant in identifying the proper position of discharge apertures suchas discharge aperture 747 (shown in FIGS. 7 and 8).

Alternatively or additionally, an external mark (stripe, groove, etc.)may be made on outer surface 1212 of pipe 1210, to designate the radialalignment of emitter 1200 within pipe 1210.

Various detection means, including electromagnetic detection methods andapparatus, may be utilized to determine a position of the drip emitterwithin the pipe. Such methods and apparatus may include, but are notlimited to, X-ray imaging or infra-red imaging.

As used herein in the specification and in the claims section thatfollows, the term “functionally passive section”, with respect to anemitter or emitter body, refers to a section disposed towards adownstream end of the water flowpath, i.e., downstream of the pressurereduction section, and any pressure control section.

As used herein in the specification and in the claims section thatfollows, the term “functionally active section”, with respect to anemitter or emitter body, is meant to include a section in which thepressure is controlled and/or reduced. The term “functionally activesection” is further meant to include a liquid inlet section such asfiltration or liquid inlet section 320 shown in FIG. 3.

As used herein in the specification and in the claims section thatfollows, the term “pressure-reducing section”, with respect to a dripemitter, is meant as used by those of skill in the art of dripirrigation emitters. One typical type of pressure-reducing section is alabyrinth-containing section.

It will be appreciated that certain features of the invention, whichare, for clarity, described in the context of separate embodiments, mayalso be provided in combination in a single embodiment. Conversely,various features of the invention, which are, for brevity, described inthe context of a single embodiment, may also be provided separately orin any suitable sub-combination.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

1. A liquid delivery system comprising: (a) a pipe having an innersurface and an outer surface, and at least a first aperture providingfluid communication between said surfaces; (b) a drip emitter disposedwithin said pipe, said emitter including: (i) an emitter body having anouter facing, and an inner facing, said outer facing having a generallyconvex contour adapted in generally complementary fashion to a concavecontour of said inner surface, said outer facing secured to said innersurface, said body having a length L; (ii) a liquid inlet sectionadapted to receive a liquid from within said pipe, and to deliver saidliquid to said outer facing; (iii) at least one pressure-reducingsection disposed in fluid communication with said liquid inlet section;(iv) functionally active sections including at least saidpressure-reducing section and said liquid inlet section, saidfunctionally active sections having a total length La, said functionallyactive sections disposed within, and longitudinally defining, a positionof at least one longitudinal segment of said emitter body; and (v) atleast one functionally passive section, disposed on said outer facing,at least partially within said longitudinal segment; and (c) a liquidflow path fluidly connecting between said liquid inlet section and saidpassive section, via said pressure-reducing section, and between saidpassive section and an ambient environment, via said aperture, whereinsaid aperture is situated within longitudinal bounds of saidlongitudinal segment, and said aperture is radially aligned with aportion of said functionally passive section disposed within saidlongitudinal segment; said outer facing spanning, in at least onelocation, an arc corresponding to an angle of at least 140° of saidinner surface of said pipe.
 2. The system of claim 1, wherein saidfunctionally active sections include a pressure-controlling section. 3.The system of claim 1, wherein said functionally active sections consistof said pressure-reducing section, said liquid inlet section, and apressure-controlling section.
 4. The system of claim 1, wherein saidfunctionally active sections consist of said pressure-reducing sectionand said liquid inlet section.
 5. The system of claim 1, wherein alength ratio of said length La to said length L of said emitter body isat least 0.60. 6.-12. (canceled)
 13. The system of claim 5, said innerfacing having a diameter D, wherein an aspect ratio of said diameter Dto said length L is at least 0.25. 14.-15. (canceled)
 16. The system ofclaim 5, said outer facing spanning, in at least one location, an arccorresponding to an angle of at least 180° of said inner surface.17.-20. (canceled)
 21. The system of claim 5, wherein said emitter bodyis generally cylindrical over all of said length La.
 22. The system ofclaim 5, wherein said emitter body is generally cylindrical over all ofsaid length L.
 23. The system of claim 5, wherein said pressure-reducingsection includes at least one labyrinth channel.
 24. The system of claim5, wherein a distance between a first end of said emitter body and aproximal end of said functionally active sections disposed proximally tosaid first end, is less than 9 mm. 25.-27. (canceled)
 28. The system ofclaim 5, wherein said functionally active sections are substantiallylongitudinally continuous with respect to said body.
 29. The system ofclaim 5, wherein said pipe has at least one additional aperture disposedtherethrough, said additional aperture situated within said length L,but longitudinally outside of said longitudinal segment of said dripemitter.
 30. The system of claim 5, wherein said liquid inlet sectionincludes a filtration section.
 31. The system of claim 5, wherein saidouter surface of said pipe has at least one protrusion indicating aradial alignment of said emitter within said pipe.
 32. The system ofclaim 31, wherein said emitter has at least one alignment protrusion insaid outer facing, said alignment protrusion at least partiallyprotruding into said pipe.
 33. The system of claim 5, wherein said outersurface of said pipe has at least one mark, groove, or other externalfeature indicating a radial alignment of said emitter within said pipe.34. The system of claim 5, wherein an opening passes through saidemitter body, whereby an inner facing of said body and said outer facingare in fluid communication, said liquid inlet section adapted to receivesaid liquid from within said pipe, via said inner facing, and to deliversaid liquid, via said opening, to said outer facing.
 35. The system ofclaim 5, wherein said functionally passive section is disposedcompletely within said longitudinal segment. 36.-51. (canceled)
 52. Anin-line drip irrigation emitter comprising: (a) an emitter body havingan inner facing and an outer facing, said body adapted to be secured toa substantially cylindrical inner surface of an irrigation pipe, saidouter facing having a generally convex contour adapted in generallycomplementary fashion to a concave contour of an imaginary cylindricalsurface enveloping said outer facing and impinging thereupon, said outerfacing spanning, in at least one location, an arc corresponding to anangle of at least 140° of said imaginary cylindrical surface, said innerfacing having a diameter D, and said body having a length L; (b) a fluidinlet section having at least one opening, said opening passing throughsaid body whereby said inner facing and said outer facing are in fluidcommunication; (c) at least one functionally active section selectedfrom the group of sections consisting of a pressure-reducing section,said fluid inlet section, and a pressure-controlling section, said atleast one active section having a length La, said at least one activesection disposed within, and longitudinally defining, a position of asingle, or at least one, longitudinal segment of said emitter body; (d)at least one functionally passive section, disposed on said outerfacing, at least partially within said longitudinal segment; and (e) afluid flow path, whereby, when said outer facing is secured against saidcylindrical inner surface of said irrigation pipe: said passive sectionis disposed in fluid communication with said functionally activesection; and said fluid flow path fluidly connects between said fluidinlet section and said functionally passive section, via each one ofsaid at least one functionally active section; wherein a length ratio ofsaid length La to said length L of said emitter body is at least 0.70;and wherein an aspect ratio of said diameter D to said length L is atleast 0.30. 53.-54. (canceled)